The practice of aging distilled alcoholic spirits or liquors to improve their bouquet, flavor and color is well known and in widespread use. Conventionally, such aging treatment is carried out by placing the new or unaged alcoholic spirits in wooden barrels provided with an internal charred surface, and thereafter placing the barrel in a warehouse maintained at a controlled ambient temperature for a period of years depending upon the specific type of distilled spirits and the governmental regulations applicable to provide a truly or fully aged liquor. Normally, the barrel is intermittently moved or rotated to prevent sections thereof from drying out and to provide agitation of the liquor therein. During the course of the aging treatment, the liquor permeates or diffuses into the wooden container, which undergoes "breathing" as a result of fluctuations in the ambient temperature within a relatively narrow range. Over prolonged aging periods, such as 4 years or more, for example, a substantial loss in the original unaged whiskey occurs as a result of evaporation of both water and alcohol as it diffuses through the wooden barrel, as well as that quantity of alcohol which becomes absorbed in the interstices of the wood and cannot be recovered at the conclusion of the aging process. Losses in amounts of about 15-20% or more are not uncommon over aging periods of about 4 years. Not only are such losses of valuable alcoholic spirits undesirable from a cost standpoint, but the dissipation of such spirits in the form of vapors in the warehouse constitutes a health and fire hazard to personnel.
Various attempts have heretofore been proposed to improve the method of effecting a full aging of alcoholic distilled spirits, including various devices for increasing the efficiency and/or effectiveness of the aging treatment. Exemplary of such new devices and techniques are those disclosed in U.S. Pat. Nos. 864,896; 2,017,235; 2,114,009; 2,586,133; 2,657,629; and 3,372,633. Apparatuses and techniques as disclosed in the aforementioned United States patents have not been successful for one or a number of reasons in reducing the warehousing costs associated with the aging process and the loss of valuable spirits over the aging period. In addition to the foregoing techniques, attempts have also been made to increase the effectiveness of the aging treatment by increasing the area of charred wood exposed to contact by the distilled alcoholic spirits, such as by introducing a quantity of charred wood chips or flakes into the barrels, by using grooved charred sticks, by using charred wooden baffles, and the like. While certain benefits have been realized as a result of such deviations from conventional barrel-type aging processes, the magnitude of such advantages are frequently more than offset by the costs and other problems introduced by such modifications, thereby discouraging widespread adoption of such techniques.
The apparatus and method of the present invention overcomes many of the problems and disadvantages associated with prior art techniques employed for effecting a full or true aging of distilled alcoholic spirits by materially reducing size requirements of a warehouse for aging a given volume of liquor, by recovering and recirculating volatilized constituents formed during the aging process, by increasing the efficiency of the aging treatment providing for improved aged liquors, and by substantially reducing the costs in labor and equipment for effecting a full or true aging of alcoholic spirits.